42-year-old Juan Padilla is accused of shooting 46-year-old Terry Luukkonen in the head at Genesis Attachments in May 2013.

Prosecutors claim Padilla killed Luukonen because he was upset that Luukonen's fiancée, Christen Weir, who used to date Padilla, had broken up with him.

A year ago in July Padilla pleaded not guilty to the charges.

Last week the defense notified the state of his change of heart.

"It was Juan's desire not to have to put the families involved through the trauma of a trial," said J. Patrick O'Neill Jr.

Prosecutor Dan Blank says a guilty plea is very rare in murder cases.

He says he's shocked that this case won't go to trial.

"It's gotta reflect the strength of the case, the strength of the family members of Mr. Luukonen, our victim, but also the strength of the police investigation, the strength of the court process and maybe the strength of a person to accept responsibility for murder," said Dan Blank, Douglas County District Attorney.

Luukkonen's family and friends were emotional during the hearing.

Blank hopes the guilty plea will help bring some kind of closure.

"As tragic as it was, with the whole senseless motive, resolve in a plea, I think was a true sense of justice," said Blank.

Under Wisconsin law, sentencing for first degree murder is life in prison.

As part of a plea bargain, Blank agreed to recommend that Padilla be eligible for parole after 20 years in prison.